Depends where you are. Prefab houses in Germany have become quite normal. This article for 2018 says 20% of new houses in Germany are prefabricated. Meanwhile

Depends where you are. Prefab houses in Germany have become quite normal. This article for 2018 says 20% of new houses in Germany are prefabricated. Meanwhile the Swiss are developing robots that build houses... https://youtu.be/fxxcEw98Njo https://youtu.be/fxxcEw98Njo